Design and Analysis of an Electric Hydraulic Hybrid Powertrain in Electric Vehicles

Abstract

An electric hydraulic hybrid (EH2) powertrain for urban vehicles has been introduced and evaluated in this paper. The high power density hydraulic system in parallel configuration reduces the electricity consumption and the battery discharging stress of the electric powertrain, which extends the vehicle driving range and improves the battery pack lifespan. The proposed EH2 powertrain has been integrated to a city delivery truck model and a city bus model, evaluated over six corresponding driving cycles, respectively. Based on the simulation results, the city delivery truck battery discharging stress could be reduced by 30% on average and the city bus driving range could be extended by 50% in the best scenario. A scaled down prototype has been built and the experimental results validate the benefits of the EH2 powertrain.